... . 2)ECO-Friendly 3)big screen 4)auto-power-off. descriptioncheck and correct electronic calculator Autumn Festival1)12 digits ... numbers.3)dual power supply ( solar and battery).4)99 steps reply to check each process. and it can correct ... the mis-input .5)it switch the power off automatially if there has been no key entered for ... clearly with big screen.7)magnet on the back. immo code calculator